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Fast and lightweight set for unsigned 32 bits integers.

Project Description

An efficient and light-weight ordered set of 32 bits integers. This is a Python wrapper for the C library CRoaring.

The wrapping used to be done with Ctypes. We recently switched to Cython for the following reasons:

  • Much better performances for short function calls (e.g. addition/deletion of a single element).
  • Easier installation, no need to install manually the C library, it is now distributed with PyRoaring.
  • Extensibility, it will be easier to write efficient codes with Cython (e.g. some data structures based on roaring bitmaps).

If for some reason you wish to keep using the old version, based on Ctypes, use PyRoaring 0.0.7.


  • Environment like Linux and MacOS
  • Python 2.7, or Python 3.3 or better
  • A recent C compiler like GCC
  • The package manager pip
  • The Python package hypothesis (optional, for testing)
  • The Python package Cython (optional, for compiling pyroaring from the sources)
  • The Python package wheel (optional, to build a wheel for the library)


To install pyroaring on your local account, use the following command:

pip install pyroaring --user # installs PyRoaringBitMap

For a system-wide installation, use the following command:

pip install pyroaring

Naturally, the latter may require superuser rights (consider prefixing the commands by sudo).

If you want to use Python 3 and your system defaults on Python 2.7, you may need to adjust the above commands, e.g., replace pip by pip3.

Manual compilation / installation

If you want to compile (and install) pyroaring by yourself, for instance to modify the Cython sources or because you do not have pip, follow these steps. Note that the Python package Cython is required.

Clone this repository.

git clone
cd PyRoaringBitMap

Build pyroaring locally, e.g. to test a new feature you made.

python build_ext -i
python # run the tests, optionnal but recommended

Install pyroaring (use this if you do not have pip).

python install # may require superuser rights, add option --user if you wish to install it on your local account

Package pyroaring.

python sdist
pip install dist/pyroaring-0.1.?.tar.gz # optionnal, to install the package

Build a wheel.

python bdist_wheel

For all the above commands, two environment variables can be used to control the compilation.

  • DEBUG=1 to build pyroaring in debug mode.
  • ARCHI=<cpu-type> to build pyroaring for the given platform. The platform may be any keyword given to the -march option of gcc (see the documentation). Note that cross-compiling for a 32-bit architecture from a 64-bit architecture is not supported.

Example of use:

DEBUG=1 ARCHI=x86-64 python build_ext


First, you can run the tests to make sure everything is ok:

pip install hypothesis --user

You can use a bitmap nearly as the classical Python set in your code:

from pyroaring import BitMap
bm1 = BitMap()
bm2 = BitMap([3, 27, 42])
print("bm1       = %s" % bm1)
print("bm2       = %s" % bm2)
print("bm1 & bm2 = %s" % (bm1&bm2))
print("bm1 | bm2 = %s" % (bm1|bm2))


bm1       = BitMap([3, 18])
bm2       = BitMap([3, 27, 42])
bm1 & bm2 = BitMap([3])
bm1 | bm2 = BitMap([3, 18, 27, 42])


Pyroaring is compared with the built-in set and other implementations:

The script measures the time of different set operations. It uses randomly generated sets of size 1e6 and density 0.125. For each operation, the average time (in seconds) of 30 tests is reported.

The results have been obtained with:

  • CPU Intel i7-7820HQ
  • CPython version 3.5.3
  • gcc version 6.3.0
  • pyroaring commit 6c86765d0357492895fee99de8841ce42340f879
  • python-croaring commit 3aa61dde6b4a123665ca5632eb5b089ec0bc5bc4
  • roaringbitmap commit a32915f262eb4e39b854d942e005dc7381796808
  • sortedcontainers commit 53fd6c54aebe5b969adc87d4b5e6331be1e32079
operation pyroaring python-croaring roaringbitmap set sortedcontainers
range constructor 1.08e-04 1.14e-04 8.89e-05 4.18e-02 1.33e-01
ordered list constructor 2.58e-02 5.25e-02 1.01e-01 1.23e-01 3.88e-01
list constructor 9.18e-02 1.05e-01 1.26e-01 6.80e-02 3.47e-01
ordered array constructor 4.07e-03 5.05e-03 2.19e-01 6.30e-02 2.13e-01
array constructor 8.55e-02 9.11e-02 3.88e-01 1.05e-01 3.63e-01
element addition 1.48e-07 5.23e-07 1.45e-07 1.06e-07 9.74e-07
element removal 1.40e-07 5.41e-07 1.26e-07 1.02e-07 4.41e-07
membership test 7.39e-08 6.59e-07 8.03e-08 5.90e-08 3.74e-07
union 1.03e-04 1.37e-04 1.02e-04 1.03e-01 7.09e-01
intersection 8.44e-04 8.05e-04 7.90e-04 3.73e-02 1.20e-01
difference 1.02e-04 1.40e-04 9.97e-05 9.24e-02 3.16e-01
symmetric diference 1.02e-04 1.36e-04 9.81e-05 1.34e-01 5.94e-01
equality test 5.36e-05 5.62e-05 4.30e-05 1.56e-02 1.53e-02
subset test 6.97e-05 6.00e-05 5.91e-05 1.54e-02 1.55e-02
conversion to list 3.37e-02 2.12e-01 3.18e-02 3.50e-02 3.83e-02
pickle dump & load 2.25e-04 3.56e-04 2.47e-04 1.46e-01 3.88e-01
“naive” conversion to array 3.35e-02 2.25e-01 3.16e-02 6.39e-02 6.10e-02
“optimized” conversion to array 1.20e-03 2.42e-02 nan nan nan
selection 7.69e-07 3.76e-05 1.13e-06 nan 8.57e-06
slice 3.23e-03 2.35e-01 1.23e-01 nan 5.76e-01
Release History

Release History

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File Name & Checksum SHA256 Checksum Help Version File Type Upload Date
pyroaring-0.1.6.tar.gz (240.9 kB) Copy SHA256 Checksum SHA256 Source Sep 21, 2017

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